Storage system controlling power supply module and fan

ABSTRACT

When a disk device corresponding to a logical volume is started, a disk system determines and starts a disk device and a fan to be started, while comprehensively considering heat quantity generated by the disk device to be started, the cooling capacity of the fan, and the electric power consumption of the fan or the electric power consumption of the disk device.

This application relates to and claims priority from Japanese PatentApplication No. 2005-255823, filed on 5 Sep. 2005, the entire disclosureof which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an art of realizing a storage system oflow cost, long life span, low electric power consumption.

2. Description of the Related Art

In recent years, the amount of information held by enterprises hasincreased and the inventory of storage systems, such as disk arrays, tostore the information has also increased. Therefore, information systemmanagers of the enterprises need to manage a large number of storagesystems. Thus, a movement to put together a larger number of storagesystems into a large-scale storage system is brisk. If the large-scalestorage system is run, it is necessary to consider a reduction in theelectric power consumption of the storage system and cooling of heatgenerated.

JP-A Nos. 2000-293314 and 2005-157710 disclose a technique of allowingdisk devices to transit to a power saving mode or turning off powersupply modules of the disk devises, in order to save energy consumed bythe disk devices.

Meanwhile, JP-A No. 2000-149542 discloses a technique of changing thenumber of rotations of fans in the storage system to appropriately coolthe storage system, in conjunction with the structure of the storagesystem.

SUMMARY OF THE INVENTION

Since a cooling device (for example, a fan, hereinafter referred to as“fan”) used for cooling the storage system also consumes electric powerin actuality, it is necessary to consider the electric power consumptionof the fan when a reduction in the electric power consumption of thestorage system is taken into consideration. However, if the fan is notappropriately operated, the storage system cannot be cooled well, and inthe worst case, there is a possibility that the data stored in thestorage system may be destructed. In other words, it is necessary tocontrol the electric power consumption and the cooling capacity of thestorage system in correlation with each other.

However, JP-A Nos. 2000-293314 and 2005-157710 do not consider thecooling, and the JP-A No. 2000-149542 does not consider the electricpower consumption at all.

In the present specification, as a configuration in which the electricpower consumption of the storage system is reduced while the coolingcapacity thereof is maintained, the following configuration isdisclosed. That is, in a storage including a controller, a disk deviceconnected to the controller, a cooling device that cools the diskdevice, and a power supply module that supplies electric power to thecontroller, the disk device, and the cooling device, the controllerdetermines whether or not the disk device is to be started, on the basisof information concerning heat quantity generated by starting the diskdevice, the cooling capacity of the cooling device, and electric powerrequired to drive the disk device.

As another aspect, it is also conceivable to adopt a configuration inwhich the controller creates a logical volume on the basis of a storageregion in the disk device, and the controller determines whether or notthe disk device is to be started or stopped, using information onwhether or not the logical volume is to be used from other devices as atrigger.

Moreover, as still another aspect, it is conceivable to adopt aconfiguration in which the controller further determines whether or notthe cooling device is to be run. Other aspects of the invention willbecome apparent from the following description with reference to theaccompanying drawings.

According to the invention, it is possible to reduce the electric powerconsumption of the storage system, to reduce the cost of the powersupply module and the fan, and to prolong the life span of the devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary configuration of a system in a firstembodiment;

FIG. 2 shows an example of information and programs in a control memory;

FIG. 3 shows the outline of operation of the first embodiment;

FIG. 4 shows the outline of operation of the first embodiment;

FIG. 5 illustrates the relationship among a power supply module, a fan,a disk device, and a logical volume inside the disk system;

FIG. 6 shows an exemplary configuration of logical volume managementinformation;

FIG. 7 shows an exemplary configuration of disk device managementinformation;

FIG. 8 shows an exemplary configuration of power supply moduleinformation;

FIG. 9 shows an exemplary configuration of fan information;

FIG. 10 shows an exemplary processing sequence of a disk system 1100;

FIG. 11 shows another exemplary processing sequence of the disk system1100;

FIG. 12 shows an exemplary configuration of a system in a secondembodiment;

FIG. 13 shows an exemplary configuration of host logical volumeinformation;

FIG. 14 shows an exemplary processing sequence when a disk system 12000has received a host logical volume allocation request;

FIG. 15 shows another exemplary processing sequence when the disk system12000 has received a host logical volume open request;

FIG. 16 shows an exemplary configuration of a system in a thirdembodiment;

FIG. 17 shows an example of information and programs in an NAS memory.

FIG. 18 shows an exemplary configuration of logical volume counterinformation;

FIG. 19 shows an exemplary processing sequence when an NAS 16100 hasaccepted a mount request;

FIG. 20 shows another exemplary processing sequence when the NAS 16100has accepted an unmount request;

FIG. 21 shows an exemplary processing sequence when the NAS 16100 hasaccepted a file open request;

FIG. 22 shows an exemplary processing sequence when the NAS 16100 hasaccepted a file close request;

FIG. 23 shows an exemplary configuration of disk system information;

FIG. 24 shows another exemplary processing sequence of the disk system1100;

FIG. 25 shows an exemplary configuration of a system in a thirdembodiment; and

FIG. 26 shows an exemplary processing sequence of a management computer1300.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments will be described. It should be notedhere that all the embodiments are described only for the illustrativepurpose, and the invention is not limited to the embodiments.

Further, it is assumed in the following description of the embodimentsthat the “starting of a disk device” means that a disk device transitsfrom a certain state to a state in which the disk device can process aread/write request from another device (for example, a control device).Here, the “state in which a disk device can process a read/writerequest” indicates, for example, a state in which a power supply moduleof a controller in the disk device is turned on, and a recording medium(a disk (also referred to as a platter)) in the disk device has rotated.

Moreover, it is assumed that the “stopping of a disk device” means thatthe disk device transits from a started state to a state in which theelectric power consumption thereof is smaller than that of the starteddisk device. Here, the “stopped state” is, for example, a state in whichthe rotation of a platter has been stopped, a state in which acontroller in a disk device is turned off or become a power-saving mode,or the like.

FIG. 1 shows an exemplary configuration of a system to which a firstembodiment is applied. The system has a host computer 1200, a storagesystem 1000, and a fibre channel switch 1400 that connects the hostcomputer 1200 with the storage system 1000. It should be noted that thedevice for connecting the host computer 1200 with the storage system1000 may be, for example, any device, such as an IP (Internet Protocol)switch and a connecting device for a main frame, other than the fibrechannel switch 1400.

Further, the number of host computers 1200 to be connected to thestorage system 1000 may be one or more. FIG. 1 shows an example of twohost computers 1200, which are referred to as a host computer 1200A anda host computer 1200B, respectively. The host computer 1200 is a generalcomputer, and has a CPU 1210, a memory 1220, and a disk interface 1230for connection with the fibre channel switch 1400.

The storage system 1000 has a disk system 1100 and a management computer1300. The disk system 1100 and the management computer 1300 areconnected to each other over a network. In addition, it is alsoconceivable that the management computer 1300 is mounted within onehousing as a management part within the disk system 1100.

The disk system 1100 has a controller 1110, a disk device 1130, a powersupply module 1160, and fan 1150. The controller 1110 has an hostinterface 1114 connected to the fibre channel switch 1400, a diskcontrol module 1120 that controls the disk device 1130, a cash memory1115, a processor 1111, a control information memory 1113, a managementinterface 1170 that is an interface with the management computer 1300,and a controller power supply module 1116.

The disk system 1100 has one or more disk device 1130.

FIG. 1 shows an example in which the disk system 1100 has three diskdevices 1130, specifically, a disk device 1130A, a disk device 1130B,and a disk device 1130C. In addition, it is assumed in the followingdescription that a disk device 1130, which is not accessed for apredetermined period of time, stops its own operation (rotation of adisk, movement of a head, etc.) on the basis of control of the disksystem 110O or on the basis of control of the disk device 1130 itself.

The disk system 1100 provides the host computer 1200 with a logicalvolume 1140 as an virtually (or logical) storage device. The logicalvolume 1140 and the disk device 1130 may be or may not be in aone-to-one correspondence with each other. For example, one logicalvolume 1140 may be defined over a plurality of disk devices 1130. One ormore logical volume 1140 is included in the disk system 1100. FIG. 1shows an example in which the disk system 1100 has a logical volume1140A and a logical volume 1140B. Further, in the disk system 1100, aplurality of disk devices 1130 are defined as a set having a redundantconfiguration, such as RAID. Also, all or some of storage regions in thedisk device 1130 included in the set may be defined as the logicalvolume 1140. Thereby, even when the disk device 1130 included in the setfails to operate properly, it is possible to prevent the contents ofdata stored in the logical volume 1140 from being lost.

The power supply module 1160 is used to drive parts within the disksystem 1100, principally, within the disk device 1130 and the fan 1150.In the present embodiment, the disk system 1100 has a plurality of apower supply modules 1160. In each power supply module 1160, a parttaking care of electric power supply is specified. The fan 1150 is adevice that cools the interior of the disk system 1100. In the presentembodiment, the disk system 1100 has a plurality of fans 1150. For everyfan 1150, a part (mainly, the disk device 1130) or a region in thedevice to be cooled is specified. The controller power supply module1116 is a power supply module for a part included in the controller1110.

A portion of data stored in the logical volume 1140 is temporarilystored in the cash memory 1115 (also referred to as “cash 1115”).Management data, etc. of the disk system 1100 is stored in the controlmemory 1113. The cash 1115 and the control memory 1113 may be a volatilememory or a nonvolatile memory (for example, a flash memory). Further,the cash 1115 and the control memory 1113 may have redundancy in order,such as double-up. Programs and information included in the controlmemory will be described below.

The management computer 1300 is a general computer, and has a CPU 1320,a management memory 1310, a storage system interface 1330, a user inputdevice 1340 (for example, a keyboard, a mouse, etc.), a screen outputdevice (for example, there is a display device. In addition, it may be aprogram that transmits screen output to other computers). A requestissuance/creation program 1311 is stored in the management memory 1310.In addition, the request issuance/creation program 1311 is a programthat is executed by the CPU 1320 when the management computer 1300transmits to the disk system 1100 the information indicating that thepossibility of a certain logical volume 1140 to be accessed (that is,the possibility that data stored in the logical volume 1140 is used by auser) has been raised or lowered. In addition, the requestissuance/creation program may be stored in, for example, a memory in thehost computer 1200 other than the management computer 1300. In thiscase, the host computer 1200 transmits the information to the disksystem 1100 (or the storage system 1000).

FIG. 2 shows an example of information and programs included in thecontrol memory 1113. The programs included in the control program 1113are executed by the CPU 1111. In addition, as another form, it is alsoconceivable that dedicated hardware is substituted for a processor insome or all of the processing realized by a program and a processor.

Logical volume management information 2001 is information for managingthe logical volume 1140 included in the disk system 1100. Specifically,the logical volume management information 2001 includes the informationconcerning the corresponding relation between the logical volume 1140and the disk device 1130. The disk system 1100 makes an exchange ofaddresses between the logical volume 1140 and the disk device 1130. Diskdevice management information 2002 is information for managing the diskdevice 1130. Specifically, the disk device management information 2002includes information concerning operation and information concerningelectric power consumption, of each disk device 1130 included in thedisk system 1100.

Power supply module information 2003 is information for managing thepower supply module 1160. Specifically, the power supply moduleinformation 2003 includes information concerning a maximum electricpower that can be supplied by the power supply module 1160 in the disksystem 1100 and information concerning parts to which the power supplymodule 1160 supplies electric power. Fan information 2004 is informationfor managing the fan 1150 in the disk system 1100. Specifically, the faninformation 2004 includes information concerning the cooling capacity ofthe fan 1150, and information concerning parts to be cooled by the fan1150. Disk system information 2005 includes information for managingtarget values of resources consumed by the disk system 1100 or wastesthereof.

(Rock: OK)

An accessibility improvement direction acceptance program is a programexecuted by the CPU 1111 when the disk system 1100 performs starting ofparts including a fan 1150 and a disk device 1130 according to need, onthe basis of the information that the accessibility to a logical volume1140 is raised. An accessibility degradation direction acceptanceprogram is a program executed by the CPU 1111 when the disk system 1100recognizes and stops parts including a fan 1150 and a disk device 1130which can be stopped, on the basis of the information that theaccessibility to a logical volume 1140 is lowered.

An access processing program 2030 is a program executed by the CPU 1111when the disk system 1100 recognizes a disk device 1130 by using thelogical volume management information 2001 and performs datatransmission to the disk device 1130, according to a read request or awrite request to the logical volume 1140 from the host computer 1200.The access processing program is also executed by the CPU 1111 even whenthe disk system 1100 moves the data stored in the logical volume-1140according to a request from the management computer 1300. Moreover, theaccess processing program 2030 is executed by the CPU 1111 even when thedisk system 1100 executes mirroring processing required to make aplurality of disk devices 1130 a parity group that is a RAIDconfiguration, executes computation of redundant information, orexecutes data recovery processing when some of disk devices 1130included in the parity group are damaged.

A failure monitoring program 2040 is a program executed by the CPU 1111when the disk system 1100 monitors a failure occurrence situation orstate (temperature, etc, inside the devices) of a part within the disksystem. The disk system 1100 executes the failure processing programperiodically or at a specific time (for example, before execution ofspecific processing (data copy or data movement)). If a change in thestate of a part is discovered, the disk system 1100 changes, accordingto the change in the state, values of the logical volume managementinformation 2001, the disk device management information 2002(particularly, electric power consumption 7030, calorific power 7040, anin-operation flag 7050, and temperature 7060, which will be describedbelow), the power supply module information 2003 (particularly, electricpower capacity 8020, which will be described below), and the faninformation 2004 (particularly, cooling heat quantity 9020 or electricpower consumption 9030 of a fan, which will be described below).

FIGS. 3 and 4 show the outline of operation of the first embodiment.FIG. 3 shows the outline when the host computer 1200 (or the managementcomputer 1300) indicates a logical volume 1140 whose the possibility tobe accessed (accessibility) in the future has been raised among logicalvolumes 1140 defined in the disk system 1100, to the storage system 1000(or the disk system 1100).

First, the disk system 1100 receives a request including the informationconcerning logical volumes 1140 to which the accessibility has beenraised, from the host computer 1200 (or the management computer 1300)(S2010) The controller 1110 of the disk system 1100 specifies all diskdevices 1130 corresponding to the logical volumes 1140 designated in thereceived information. Then, the controller 1110 confirms whether or notthere is any disk device 1130 that has not been started among thespecified disk devices 1130 (S2020). If all the disk devices have beenstarted, the controller 1110 completes the processing, and reports thecompletion to the host computer 1200 (or the management computer 1300).

If there is any disk device 1130 which has not been started, thecontroller 1110 confirms whether or not the capacity of the electricpower module 1160 is sufficient even if the disk device 1130 which havenot been started are started (S2030). Further, the controller 1110confirms whether or not there is any fan 1150 to be started by thestarting of the disk device 1130. Moreover, the controller 1110 confirmswhether or not sufficient cooling is possible from the viewpoint of theperformance of the fan 1150 to be started (S2040) If needed, thecontroller 1110 also determines other conditions. If the conditions aresatisfied, the controller 1110 performs starting of a required diskdevice 1130 and a fan 1150, and reports completion of the processing tothe host computer 1200 (or the management computer 1300) (S2050). Bydoing so, in the present embodiment, the fan 1150 can be startedsimultaneously with start of generation of heat caused by the startingby the disk device 1130. Therefore, rapid cooling becomes possible.Also, since the fan 1150 is not unnecessarily driven, the electric powerconsumption can be reduced.

FIG. 4 shows the outline when the host computer 1200 (or the managementcomputer 1300) indicates logical volumes 1140 whose possibility to beaccessed (accessibility) in the future have been lowered among logicalvolumes 1140 defined in the disk system 1100, to the storage system 1000(or the disk system 1100).

First, the disk system 1100 receives a request including the informationconcerning logical volumes 1140 to which the accessibility has beenlowered, from the host computer 1200 (or the management computer 1300)(S3010). The controller 1110 of the disk system 1100 specifies all diskdevices 1130 defined by the logical volumes 1140 designated in thereceived information. Next, the controller 1110 searches whether or notthere is any disk device 1130 which may be stopped among the specifieddisk devices 1130, as the accessibility of the designated logicalvolumes 1140 is lowered. If there is no disk device 1130 which may bestopped, the controller 1110 completes the processing, and reports thecompletion to the host computer 1200 (or the management computer 1300).

If there is any disk device 1130 which may be stopped, the controller1110 stops the disk device 1130. After that, the controller 1110notifies the host computer 1200 of the completion of the processing(S3020). Next, the controller 1110 confirms whether or not there is anyfan 1150 that may be stopped, as the disk device 1130 is stopped, and ifany, stops the fan (S3030). In this way, in the present embodiment, thedisk device 1130 for which starting is unnecessary is stopped, so thatthe calorific power can be lowered and the fan 1150 can be stoppedsimultaneously. Therefore, unnecessary electric power can be reduced andthe volume of operation sound of the fan can be decreased.

Hereinafter, the first embodiment will be described in detail referringto FIG. 5. FIG. 5 shows an example of the system in FIG. 1. In thisfigure, only the elements necessary for explaining the system in detailare extracted.

In FIG. 5, it is assumed that the disk system 1100 has two power supplymodules 1161 and 1162, two fans 1151 and 1152, and eight disk devices1131, 1132, 1133, 1134, 1135, 1136, 1137 and 1138. In addition, numbersafter the “ID=” in parentheses in FIG. 5 represent identifiers allocatedto respective parts.

The power supply module 1161 supplies electric power to the fan 1151,the disk device 1131, the disk device 1133, the disk device 1135, andthe disk device 1137. The power supply module 1162 supplies electricpower to the fan 1152, the disk device 1132, the disk device 1134, thedisk device 1136, and the disk device 1138. The fan 1151 cools the diskdevice 1131, the disk device 1132, the disk device 1133, and the diskdevice 1134. The fan 1152 cools the disk device 1135, the disk device1136, the disk device 1137, and the disk device 1138.

The logical volume 1141 is composed of all or some data regions of thedisk devices 1131 and 1132. The logical volume 1142 is composed of allor some data regions of the disk devices 1133 and 1135.

FIG. 6 shows an exemplary configuration of the logical volume managementinformation 2001 in the configuration shown in FIG. 5. The logicalvolume management information 2001 has entries shown below for everylogical volume 1140 (specifically, logical volumes 1141 and 1142 in FIG.5).

A logical volume identifier 6010 is an entry with which informationconcerning an identifier given to the logical volume 1140 is registered.A RAID type 6020 is an entry with which information representing aredundant configuration (for example, RAID 5 or RAID 1) of the diskdevice 1130 corresponding to the logical volume 1140 is registered. Adisk device number 6030, a starting address 6040, and an ending address6050 are entries with which information concerning the number of thedisk device 1130 corresponding to the logical volume 1140, andinformation concerning starting addresses and ending addresses thatstore data are registered. If the logical volume 1140 is defined basedon a plurality of disk devices 1130, it is natural that respectiveentries of a disk device number 413, a starting address 414, and anending address 415 are prepared by the number of corresponding diskdevices 1130.

Capacity 6060 is an entry with which information concerning storagecapacity as seen from the host computer 1200 of the logical volume 1140is registered. An access flag 6070 is an entry with which information ofthe accessibility to the logical volume 1140 is registered. In thepresent embodiment, it is assumed that, when an entry of the access flag6070 is turned on, the accessibility to a corresponding logical volume1140 is being raised.

Regarding information concerning the entries other than the entry 6070,when a logical volume 1140 is set in the disk system 1100, theinformation is set in the entries for every logical volume 1140. Thecontroller 1110 of the disk system 1100 performs the setting of thelogical volume on the basis of a direction (the capacity of the logicalvolume, etc.) of the management computer 1300. At the time of thesetting of the logical volume 1140, the controller 1110 registersinformation in the logical volume management information 2001 inconjunction with the setting. In addition, for the entry 6070, thecontroller 1110 registers a flag when information has been received fromthe host computer 1200 (or the management computer 1300).

FIG. 7 shows an exemplary configuration of the disk device managementinformation 2002 in the configuration shown in FIG. 5. The disk devicemanagement information 2002 has entries that register information shownbelow for every disk device 1130 (specifically, disk devices 1131, 1132,1133, 1134, 1135, 1136, 1136, 1137, and 1138 in FIG. 5).

A disk device identifier 7010 is an entry with which informationconcerning an identifier of the disk device 1130 is registered. Physicalcapacity 7020 is an entry with which information concerning the storagecapacity of the disk device 1130 is registered. Electric powerconsumption 7030 is an entry with which information concerning theelectric power consumption of the disk device 1130 is registered.Calorific power 7040 is an entry with which information concerning thecalorific power of the disk device 1130 is registered. An in-operationflag 7050 is an entry with which information indicating whether or notany disk device 1130 is in operation is registered. Temperature 7060 isan entry with which information concerning the temperature of the diskdevice 1130 is registered.

Among these entries, the information other than the entry 7060 may beset in advance at the time of factory shipment. This is because it isconvenient that information concerning the specification of the diskdevice 1130 is set by a vendor. It should be noted here that these kindsof information may be input from the management computer 1300, etc. Ifany new disk device 1130 is added, the entry information concerning thedisk device 1130 to be added is registered from the management computer1300, etc.

In addition, it is conceivable that the temperature 7060 is set byplacing a thermometer in the disk device 1130, and making the disksystem 1100 execute the failure monitoring program 2040 to confirmoutput of the thermometer periodically. However, the measurement of thetemperature of the disk device 1130 and the setting of the informationmay be performed by any other methods.

FIG. 8 shows an exemplary configuration of the electric power moduleinformation 2003 in the configuration shown in FIG. 5. The electricpower module information 2003 has entries that register the followinginformation for every electric power module 1160 (specifically, electricpower modules 1161 and 1162 in FIG. 5). An electric power identifier8010 is an entry with which information concerning an identifier of theelectric power module 1160 is registered. An electric power capacity8020 is an entry with which information concerning the electric powercapacity of the electric power module 1160 is registered. Connectioninformation 8030 is an entry with which information concerning anidentifier of a part connected to a corresponding electric power module1160 is registered. If a plurality of parts are connected, informationconcerning identifiers as much as the number of the parts will beregistered. Typical parts are the disk device 1130 and the fan 1150.

FIG. 9 shows an exemplary configuration of the fan information 2004 inthe configuration shown in FIG. 5. The fan information 2004 has entriesthat register the following information for every fan 1150(specifically, fans 1151 and 1152 in FIG. 5). A fan identifier 9010 isan entry with which information concerning an identifier of the fan 1150is registered. Cooling heat quantity 9020 is an entry with whichinformation concerning the quantity of heat (hereinafter referred to as“cooling heat quantity”) capable of being cooled by the fan 1150 isregistered. Fan electric power consumption 9030 is an entry with whichinformation concerning the electric power required to operate the fan1150 is registered. A turn-on flag 9040 is an entry with whichinformation indicating that the fan 1150 is in operation is registered.Part information 9050 is an entry with which information concerning anidentifier of device to be cooled by the fan 1150 is registered. If aplurality of parts are to be cooled, information concerning theidentifiers as much as the number of the parts will be registered.Typical parts are the disk devices 1130.

The information concerning each of the entries other than the turn-onflag 9040 may be registered in advance at the time of factory shipment.For the turn-on flag 9040, the controller 1110 registers the informationthat, when the controller 1110 operates a fan 1150, the fan is inoperation.

FIG. 23 shows an exemplary configuration of the disk system information2005. Target electric power 23010 is an entry that registers informationconcerning an electric power to be targeted by the disk system 1100.Target calorific power 23020 is an entry that registers informationconcerning a calorific power to be targeted by the disk system 1100. Thehousing opening/closing information 23030 is an entry which exists forevery housing constituting the disk system 1100 and in which informationindicating whether or not a housing is in an opened state (for example,a state in which a cover is removed, or a state in which a door or ashutter is opened) or a closed state is registered.

In addition, it is conceivable the target electric power and the targetcalorific power are input by setting by a manager. In addition, asinitial values, a total of electric power consumption of parts to beincluded in the disk system 1100 may be set in the target electric powerconsumption 22010, or a total of calorific power of parts to be includedin the disk system 1100 may be set in the target calorific power 23020.The total of electric power consumption corresponds to a maximumelectric power consumption when the whole system runs, and the total ofcalorific power corresponds to a maximum calorific power when the wholesystem runs. Further, as the target electric power consumption, a totalof electric power capacity (this corresponds to a limiting electricpower in the system) of the power supply module 1160 and the powersupply module 1116 included in the disk system 1100 may be set.

Further, it is conceivable that an opening/closing sensor is installedin a cover, a door, or a shutter of the disk system 1100, which executesthe failure monitoring program 2040, whereby the housing opening/closingstate is set based on opening/closing information output by the sensor.It should be noted here that the housing opening/closing state may beset by detection of the opening/closing by the disk system 1100 throughother methods.

FIGS. 10 and 24 show an exemplary processing sequence of the disk system1100 when the disk system 1100 has received information (request) thatthe accessibility to a certain logical volume 1140 (here, the logicalvolume 1142 in FIG. 5) is raised, from the host computer 1200. Inaddition, this processing can be achieved as the CPU 1111 executes theimprovement direction acceptance program 2010.

The controller 1110 receives information concerning a logical volume1140 (here, the local volume 1142) to which the accessibility is raised(S10001). Next, the controller 1110 searches the logical volumemanagement information 2001 with respect to the logical volume 1142, andspecifies a disk device 1130 (here, disk devices 1133 and 1135)corresponding to the logical volume 1142 (S10002). Next, the controller1110 checks the in-operation flag 7050 of the disk device managementinformation 2002 to investigate whether or not there is any disk device1130 (in this case, it is assumed that the disk device 1133 is not beingoperated) which is not started, among the disk devices 1130 (S10003).

If there is any disk device 1130 that is not started, the controller1110 searches the fan information 2004 to specify a fan 1150 (here, thefan 1151) that cools the disk device 1130 that is not operated. At thetime, the controller 1110 confirms whether or not the specified fan 1150is being driven (S10004).

Next, the controller 1110 calculates a calorific power to be cooled byeach fan 1150 specified in S10004 when the disk device 1130 specified inS10003 have been started, using the fan information 2004 and the diskdevice management information 2002 (S10005). Thereafter, the controller1110 compares the calculated calorific power with the cooling heatquantity 9020 of the fan 1150 (S10006).

If the calorific power calculated for all the fans 1150 (including a fan1150 which is not driven) specified in S10004 does not exceed thecooling heat quantity of the fans 1150, the controller 1110 calculatesthe calorific power of the whole system 1100 when the disk device 1130specified in S10003 has been newly started (S10101). Thereafter, thecontroller 1110 compares the calculated total of calorific power with atarget heat quantity registered in the disk device information 2005(S10102).

If the calculated calorific power is lower than the target heatquantity, the controller 1110 calculates, for every power supply module1160, an electric power to be supplied by each power supply module 1160when its is assumed that the disk device 1130 specified in S10002 and afan 1150 which is not operated among the fans 1150 specified in S10004are additionally started, using the power supply module information2003, the fan information 2004, and the disk device managementinformation 2002 (S10007). Thereafter, the controller 1110 compares theelectric power calculated for each power supply module 1160 with theelectric power capacity of the power supply module 1160 registered inthe power supply module information 2003 (S10008).

In all the power supply modules 1160, if the calculated electric powerdoes not exceed the power supply module capacity registered in the powersupply module information 2003, the controller 1110 calculates theelectric power consumption of the overall disk system 1100 when its isassumed that the disk device 1130 specified in S10003 and a fan 1150which is not operated among the fans 1150 specified in S10004 areadditionally started (S10201) Next, the controller 1110 compares thecalculated electric power consumption of the overall disk system 1100with a target electric power registered in the disk device information2005 (S10202).

If the calculated electric power consumption is lower than the targetelectric power, the controller 1110 starts the disk device 1130specified in S10003 and a fan 1150 that is not driven among the fans1150 specified in S10004, and sets the in-operation flag 7050 and theturn-on flag 9040 to ON (S10009). If no disk device 1130 to be startedexists, or after the completion of the processing in S10009, thecontroller 1110 set the access flag 6070 of the logical volume 1140received in S10001 to ON, reports the result to the host computer 1200,and then completes the processing (S1OO10).

In addition, the information at the time of the report may simplyinclude information concerning direction acceptance completion or mayinclude information concerning the started disk device 1130 and fan1150.

If the heat quantity generated by the starting of the disk device 1130exceeds the cooling capacity of the fan 1150, if the heat quantity isgreater than the target calorific power, or if the electric powerexceeds the power supply module capacity or become more than the targetelectric power, the controller 1110 inserts a request for raising theaccessibility of the logical volume 1140 received in S10001 into therearmost end of a waiting queue, reports the result to a request source,and then completes the processing. The information at the time of thereport may include information concerning direction acceptancenon-completion. Further, the information received in S10001 may includeinformation that it is unnecessary to insert the request into thewaiting queue, or if it can be seen that the insertion is unnecessarythrough other methods, the insertion of the request into the waitingqueue may be omitted. The request stored in the waiting queue is againexecuted by the controller 1110 after a predetermined period of time haslapsed or by a specific trigger.

In addition, it may be determined in S10006 whether or not it ispossible to cool the disk device 1130 (including any disk device 1130 tobe additionally started) with only the fan 1150 which has already beendriven, among the specified fan 1150 (including a fan which is notdriven), by the configuration (for example, when a plurality of fans1150 commonly take charge of cooling of one or a plurality of diskdevices 1130) of the system. If it is possible to perform the coolingwith only the fan 1150 that is being running, the controller 1110 mayperform the processing that the driving of a fan 1150 that is not drivenis not considered in the subsequent processing.

(Rock: OK)

FIG. 11 is a flow showing an example of processing of the disk system1100 when the disk system 1100 has received the information that theaccessibility to a certain logical volume 1140 is lowered, from the hostcomputer 1200 (or the management computer 1300). This processing can beachieved as the CPU 1111 executes a direction acceptance program.

The controller 1110 receives information concerning a logical volume1140 to which the accessibility is lowered (S11001). The controller 1110searches the logical volume management information 2001 to specify alldisk devices 1130 defined by the logical volume 1140 corresponding tothe information (S11002). Then, the controller 1110 confirms whether ornot there is any disk device 1130 which may be stopped among thespecified disk devices 1130. Specifically, the controller 1110 checksthe in-operation flags 7050 of the specified disk devices 1130 in thedisk device management information 2002 to specify a disk device 1130which are being driven. After the disk device 1130 which may be stoppedis specified, the controller 1110 confirms whether or not the diskdevice 1130 is allocated to other logical volumes 1140. If the diskdevice is also allocated to other logical volumes 1140, the specifieddisk device 1130 cannot be stopped. Thus, the controller 1110 excludessuch a disk device 1130 from the disk devices 1130 which may be stopped(S11003).

If the disk device 1130 which may be stopped is specified, thecontroller 1110 stops the specified disk device 1130 and set acorresponding in-operation flag 7050 to OFF (S11004). Further, thecontroller 1110 confirms whether or not there is any fan 1150 which maybe stopped by the stopping of the specified disk device 1130.Specifically, the controller 1110 specifies the fan 1150 (S11005) thatall the disk devices 1130 to be cooled will stop, as the specified diskdevice 1130 is stopped (S11005)

The controller 1110 stops the specified fan 1150, and then registers OFFinformation in the turn-on flag 9040 of a corresponding fan 1150(S11006). If there is no disk device 1130 which may be stopped or afterthe processing in S11006, the controller 1110 registers OFF informationin the access flag 6070 of the logical volume 1140 designated in thereceived information, and transmits the result to the host computer 1200(S11007).

Thereafter, the controller 1110 sequentially extracts the informationconcerning logical volumes which are registered in the waiting queue andto which the accessibility has been raised, and executes theaccessibility improvement direction acceptance program (S11008).Thereby, the remaining power of electric power and heat quantitygenerated by newly stopping the disk device 1130 and the fan 1150 can beused for starting of any one or both of the disk device 1130 and the fan1150 for improvement of the accessibility of other logical volumes.

In addition, in the above-described processing, the fan 1150 has beenconsidered in terms of the driving and stopping only. However, if thenumber of rotations of a fan can be controlled, when any disk device1130 to be started is specified, the controller 1110 may perform acontrol to increase the number of rotations of a fan 1150 to cool thedisk device 1130. Conversely, if any disk device 1130 to be stopped isspecified, the controller 1110 may perform a control to reduce thenumber of rotations of a fan 1150 to cool the disk device 1130.

By doing so, for example, when one fan 1150 takes care of cooling offour disk devices 1130 and one disk device 1130 of the disk devices isstopped, the controller 1110 decreases the number of rotations of thedisk device 1150 down to the number of rotations at which the fan cancool the other three disk devices 1130, whereby the electric powerconsumption can be reduced while the other three disk devices 1130 arecooled. Further, Noise can be reduced by decrease the number ofrotation.

In addition, as a method of calculating the electric power consumption,there is a method of calculating a total of electric power consumptionin respective parts of the fan 1150 and the disk device 1130 which arebeing started or is intended to start with reference to the disk devicemanagement information 2002 or the fan information 2004. Further, as acomparison method, a method of comparing a total value with the electricpower capacity 8020 of a corresponding power supply module 1160 isconceivable. However, as modifications, combinations with the followingmethods are also conceivable.

(1) A calculating method in which the operating state of each part isconsidered

The disk device 1130 is different in electric power consumption in astate immediately after it has been started and a state in which timehas lapsed after the starting. Further, it is also conceivable that thefan 1150 is allowed to rotate at lower speed, thereby making theelectric power consumption small instead of making the cooling heatquantity small. Further, it is also conceivable that, if a plurality offans 1150 performs the cooling of a common disk device 1130, the numberof fans 1150 to be started is increased or reduced. Therefore, as acalculating method of the electric power consumption, the electric powerconsumption of individual parts is first obtained in consideration ofthe operating state of each part, and required electric powerconsumption is then obtained from the obtained electric powerconsumption.

Further, it is also conceivable that, if the controller 1110 executesthe failure monitoring program 2040 to detect a failure leading to adecrease in the feed rate of the electric power 1160, a value from whichthe electric power supply capacity of the power supply module 1160 iscut down is compared with a calculated value in anticipation of thedecrease in the feed rate of the electric power caused by the failure.By doing so, it is possible to avoid performing the starting of the diskdevice 1130 and the fan 1150, for example, beyond the capacity of theelectric power modules 1160 even in a state of the decrease in the feedrate of the electric power. Specifically, the controller 1110 executesthe failure monitoring program 2040 periodically to monitor the state ofthe power supply module 1160. In this case, if some (for example, if thepower supply module 1160 is composed of a plurality of power supplymodules, and some of them stop due to failure) or all of the powersupply modules 1160 stop due to failure, the controller 1110 may rewritethe value of the power supply module capacity 8020 of the power supplymodule information 2003 to a value decreased due to the failure.

(2) A case in that parts such as batteries or capacitors which enabletemporary supply of electric power are included in the disk system

It is also conceivable that electric power supply parts, such asbatteries or capacitors, vary in electric power capacity. Thus, it isalso conceivable that the disk system 1100 itself confirms the state ofsuch parts to obtain changes in the electric power capacity and use thechanges for comparison. Similar to the above-described failure of thepower supply module 1160, this can be realized by checking the abovechanges by the controller 1110 to rewrite the values registered in thepower supply module information 2003.

In addition, as a method of calculating the calorific power, there is amethod of calculating a total of electric power consumption forrespective parts of disk devices 1130 which are being started or areintended to start, referring to the disk device management information2002. Further, as a comparison method, a method of comparing a totalvalue of the calorific power with the cooling heat quantity 9020 of acorresponding fan 1150 is conceivable. However, as modifications,combinations with the following methods are also conceivable.

(1) A method of calculating the calorific power in consideration of thestate of the disk device 1130

If the operating time of the disk device 1130 becomes long after it isintroduced, the calorific power increases. Therefore, it is alsoconceivable that the calorific power is obtained while the state of eachdisk device is confirmed periodically, and then the total value iscalculated from the obtained calorific power. Specifically, it ispreferable that the controller 1110 confirms the calorific power of thedisk device 1130 periodically, and then rewrites the disk devicemanagement information 2002.

(2) A calculation and comparison method in which the temperature of thedisk device 1130 is considered

In order to perform cooling in consideration of a dynamic temperaturechange of the disk device 1130, it is also conceivable to adopt a methodof adding the cooling heat quantity additionally required for coolingthe temperature of the disk device 1130 to an intended temperature, tothe calorific power of the disk device 1130. Further, although a highesttemperature of a disk device, which is being used, is specified as thespecification of the disk device, it is also conceivable to use the diskdevice at a temperature lower than the highest temperature, if thesystem is intended to use with longer life span. However, if the diskdevice is intended to operate at a low temperature within a range of thespecified cooling heat quantity, a number of disk devices 1130 cannot berun. Thus, it is desirable to adopt a configuration in which a desiredoperation mode (access priority, life span priority, etc.) may be set bya manager and the calculation and comparison is performed in response tothe setting.

(3) A method of considering changes in flow of air or cooling fluid ofthe disk system 1100

Generally, the cooling of a device is performed by moving heat generatedby the device to a fluid (for example, air or cooling water, which isreferred to as “cooling fluid”) which exists around the device, andmoving the fluid to the outside of the device. Further, fins may beinterposed for movement of the heat between the device and the coolingwater. Therefore, when the device is cooled, in addition to the specificheat, heat conductivity, and temperature of the cooling fluid, the flowrate of the cooling fluid moving around the device is related to thecooling efficiency.

However, there is a case that, when maintenance of the disk system 1100is performed, a cover of an entire or partial housing of the disk system1100 is opened. In this case, since the flow of the cooling water withinthe disk system 1100 varies, the cooling heat quantity of a fan changes(for example, lowers) compared with a case in which the housing isclosed. It is conceivable to adopt a method that performs the comparisonof the cooling heat quantity in consideration of a state change(particularly, opening and closing of the cover of the housing) thatleads to such a change in the flow of the cooling water. For example,when the controller 1110 performs the above-described processing in FIG.10, etc., the controller 1110 refers to opening/closing information22030. If the housing is found to be open, the controller 1110calculates the cooling heat quantity 9020 of the fan 1150 inconsideration of an amount of decrease in the cooling capacity toperform the processing in FIG. 11, etc., with the values.

In addition, in a case of using the present comparison method, it isalso possible to provide the outside of the disk system 1100 with theinformation which correlates the starting of the disk device with theopening/closing of the housing, such that the result that the diskdevice 1130 could not be started due to the opening/closing of thehousing, is reflected on the result of response to the host computer1200 from the disk system 1100. Further., it is also conceivable that,if the cover of the housing is opened from its closed state, the disksystem 1100 itself detects the phenomenon to stop the disk device 1130that are being driven.

Of course, the respective calorific power, electric power consumption,electric power capacity, and cooling heat quantity may be considered by,for example, calculating the electric power consumption and thecalorific power or performing the comparison, using other methods thanthe above modifications.

Further, there is a case that the disk system 1100 accesses to the diskdevice 1130 which are not driven, at a time other than the time when anaccess request including read/write from the host computer 1200 hasarrived. For example, it is conceivable that the following processing bythe disk system 1100 is executed.

(1) Parity group recovery processing, such as copy of data to sparedisks when disk devices 1130 in a parity group stop due to failure

(2) Encryption, compression and garbage collection of data included inthe logical volume

(3) Data copy and data relocation between two logical volumes inside thedisk system 1100

(4) Data copy and data relocation between different disk systems 1100

Even when such processing by the disk system 1100 accessing to the datain a disk device 1130 which is not driven, the controller 1110 canexecute the accessibility improvement direction acceptance program 2010,thereby performing the starting of the disk device 1130 and the fan 1150in consideration of the electric power consumption and the calorificpower. However, in this case, if electric power consumption or acalorific power is caused beyond the target electric power 23010 and thetarget heat quantity 22020 due to the starting of the disk device 1130,a desired disk device 1130 is not started and the controller 1110 cannotaccess to the data. As a result, the above-described processing by thedisk system 1100 sometimes does not proceed or stop. In order to notifythe manager of this situation, it is also conceivable to provide screenoutput that provides the fact that the reason of failure of theprocessing by the disk system 1100 is related to the electric powerconsumption and the calorific power.

(Rock: OK)

Further, it is also conceivable to perform exceptional processing abouthigh-priority processing on the ground that the risk of data loss ishigh as in the parity group recovery processing. For example, the disksystem 1100 or a manager sets the priority of processing contents. Ifthe disk device 1130 and the fan 1150 are started with respect to thehigh-priority processing, the disk device 1130 and the fan 1150 arestarted even if a total of electric power consumption is more than atarget electric power or a total of calorific power is more than atarget heat quantity. In this case, in the processing sequence describedreferring to FIG. 10, etc., the controller 1110 may omit the processingin Steps S10102 or S10202 according to the priority.

Moreover, in the first embodiment, the disk devices to be driven aredetermined in units of logical volumes. However, it is possible todetermine disk devices to be driven according to which disk device is tostore the data for which read or write is requested, not the units oflogical volumes.

Further, in the first embodiment, the disk device and the fan arestarted if only the request for all the electric power consumption, heatquantity, target electric power and target heat quantity is satisfied.However, it is also conceivable to adopt a configuration in which thedisk device and the fan are started in consideration of the heatquantity and the maximum electric power only. In this case, it isdesirable to set the target electric power as the maximum electricpower. Further, it is possible to adopt a configuration in which arequest to be considered can be discarded or selected by a manager.Thereby, it is possible to realize driving of the disk device accordingto a manager's request.

FIG. 12 shows an exemplary configuration of a system to which a secondembodiment is applied. The second embodiment is different from the firstembodiment in that an virtually storage region to be accessed by thehost computer 1200 is called a host logical volume 12010. In addition,the information, the programs and the hardware inside the controller1110, which are shown in FIG. 1, are omitted in FIG. 12. The hostlogical volume 12010 is an virtually logical volume that is created asthe CPU 1111 executes the access processing program 2030. The hostlogical volume 12010 is correlated with the logical volume 1140.

The controller 1110 converts the logical volume 1140 to the host logicalvolume 12010 on the basis of the access host logical volume information12030, which will be described below, to provide it to the host computer1200, and vice versa. In addition, the number of the host logical volume12010 may be specified in the upper limit number for various reasons.

Here, the second embodiment is characterized in that the host computer1200 allocates the host logical volume 12010 to only a logical volume1140 to which the accessibility has been raised so as to enable accessfrom the host computer 1200 and start any disk device 1130 which is notstarted. Further, the second embodiment is characterized in that thehost computer releases a logical volume 1140 to which the accessibilityhas been lowered from the allocation of the host logical volume 12010 soas to disable the access from the host computer 1200 and stop the diskdevice 1130, if possible.

Specifically, the system of the second embodiment operates in thefollowing manner. First, the host computer 1200 notify the disk system12000 of an identifier or an address of a logical volume 1140 to whichthe accessibility has been raised. The controller 1110 executes a hostlogical volume allocation program 12020 to notify the host computer 1200of an identifier of the host logical volume 12010 to be allocated to thenotified logical volume 1140. The host computer 1200 gets access to ahost volume virtually in the disk system 12000, using the notifiedidentifier.

Meanwhile, for a logical volume 1140 to which the accessibility has beenlowered, the host computer 1200 notifies the disk system 12000 of anidentifier the logical volume 1140 or an identifier of a correspondinghost logical volume 12010. The disk system 12000 deletes the informationconcerning the corresponding relation between the notified host logicalvolume 12010 and the corresponding logical volume 1140 from the controlprogram 1113.

In the second embodiment, the host logical volume information 12030 isprovided in the management information in the control program 1113.Here, the information concerning the corresponding relation between thehost logical volume 12010 and the logical volume 1140 is registered.

FIG. 13 shows an exemplary configuration of the host logical volumeinformation 12030. The host logical volume information 12030 has entrieswith which the following information is registered for every hostlogical volume 12010. A host logical volume identifier 13010 is an entrywith which information concerning an identifier of a corresponding hostlogical volume 12010 is registered. A logical volume address 13020 is anentry with which information concerning an identifier of a logicalvolume 1140 allocated to the host logical volume 12010 is registered.Here, if a logical volume 1140 is not allocated to the host logicalvolume 12010, it is assumed that this value is a null value. Except forthe above points, the configuration of the second embodiment is the sameas that of the first embodiment.

FIG. 14 shows an exemplary processing sequence when the disk system12000 has received information concerning a logical volume 1140 to whichthe accessibility has been raised. In addition, the following processingis performed as the CPU 1111 of the controller 1110 executes the hostlogical volume allocation program 12020.

The controller 1110 of the disk system 12000, which has receivedinformation (an identifier) about a logical volume 1140 to which theaccessibility has been raised (S14010), and executes the accessibilityimprovement direction acceptance program 2010, using the receivedidentifier (S14020).

Next, the controller 1110 confirms whether or not the disk device 1130has been started, as a result of the execution of the accessibilityimprovement direction acceptance program 2010 (S14030). If the diskdevice 1130 has been started, the controller 1110 searches a hostlogical volume 12010, to which any logical volume 1140 is not allocated,from the host logical volume information 12030. In addition, if thecontroller 1110 has received an identifier of a desired host logicalvolume 12010 additionally, the controller may search a host logicalvolume 12010 corresponding to the received identifier (S14040).

Next, the controller 1110 confirms whether or not a host logical volume12010 to meet the conditions could be found (S14050). If a host logicalvolume 12010 to meet the conditions is found, the controller 1110registers the information concerning the identifier of the logicalvolume 1140 received in the S14010, to an entry corresponding to thehost logical volume 12010 found in the host logical volume information12030. Thereafter, the controller 1110 transmits completion ofallocation including the information concerning the identifier of theallocated host logical volume 12010 to the host computer 1200 and thencompletes the processing (S14060).

On the other hand, if it is determined in Step S14030 that the diskdevice 1130 cannot be started, the controller 1110 notifies the hostcomputer 1200 of failure of the allocation and then completes theprocessing. In addition, the reasons why the disk device 1130 cannot bestarted, such as the reasons that the conditions of the calorific poweror the electric power consumption were not satisfied, may be included inthe notification at this time (S14100).

If a host logical volume 12010 to be allocated was not found, thecontroller 1110 executes the accessibility degradation directionacceptance program 2020, stops the disk device 1130 and the fan 1150, ifpossible, then notifies the host computer 1200 of failure of theallocation, and completes the processing. In addition, the reason whythe allocation of a host logical volume has failed may be included inthe notification at this time.

FIG. 15 shows an exemplary processing sequence to be executed by thedisk system 12000 when the disk system 12000 has received information oflowering of the accessibility to a logical volume 1140. This processingcan be achieved as the CPU 1111 executes the host logical volumeallocation program 12020.

The disk system 12000 receives information of an identifier of a logicalvolume 1140 or a host logical volume 12010 to which the accessibilityhas been lowered from the host computer 1200 (15010). Thereafter, thecontroller 1110 of the disk system 12000 executes the accessibilityimprovement degradation acceptance program 2020, using the receivedidentifier, and if there are any disk device 1130 and a fan 1150 whichcan be stopped, stops them (S15020). Thereafter, the controller 1110deletes the correspondence in the host logical volume information 12030between the host logical volume 12010 and the logical volume 1140(nullifies the value of the logical volume identifier 13020), notifiesthe host computer 1200 of completion of the processing, and completesthe processing (S15030).

In addition, one logical volume 1140 may correspond to a plurality ofhost logical volumes 12010, and some data regions of a host logicalvolume 12010 may correspond to all or some regions of a logical volume.In this case, it should be noted that information concerning a startingaddress and an ending address of the host logical volume 12010 andinformation concerning a starting address and an ending address of thelogical volume 1140 are added to the host logical volume information12030. In addition, the allocation and release of the host logicalvolume 12010 includes the concept of allocation and release of logicalunit numbers of SCSI and iSCSI, controller unit numbers of a main frame,LDEV numbers, etc.

FIG. 16 shows an exemplary configuration of a system to which a thirdembodiment is applied. In addition, the information, the programs andthe hardware inside the controller 1110, which are shown in FIG. 1, areomitted in FIG. 16. The difference between the third embodiment and thefirst embodiment lies in that, in the third embodiment, a controller16100 (hereinafter referred to as “NAS 16100”) implementing the NAS(Network Attached Storage) is added to the inside of the disk system16000. In addition, although the NAS 16100 exists inside the disk system16000 referring FIG. 16, as another embodiment, the NAS 16100 may existoutside the disk system 16000.

Since a protocol used for communication between the NAS 16100 and thehost computer 1200 is a normal IP, the host computer 1200 and the NAS16100 are connected to each other by an IP switch 16200, which isdifferent from the configuration in FIG. 1. Of course, the host computer1200 and the NAS 16100 may be directly connected to each other. Further,although the NAS 16100 accesses to the logical volume 1140, it mayaccess to the host logical volume 12010 described in the secondembodiment.

The NAS 16100 has a CPU 16110, an NAS memory 16120, an interface 16130for IP, and an interface 16140 for volume access. These elements areconnected to each other via internal buses or over a network. The hostcomputer 1200 transmits an access request in units of files (alsoreferred to as file I/O or file level) to the NAS 16100. The NAS 16100converts the access request in units of files to a request of access toa logical volume (also referred to as file I/O or file level) totransmit it to the controller 1110.

In the third embodiment, the NAS 16100 directs the controller 1110 touse or stop the logical volume 1140. Along therewith, the NAS 16100transmits the information concerning the accessibility of the logicalvolume 1140 that the host computer 1200 transmits in the first andsecond embodiments. Generally, files are opened immediately before use,and are closed after completion of the use. Thus, if at least one of thefiles included in a logical volume 1140 is opened, the NAS 16100determines that the accessibility of the logical volume 1140 has beenraised, to notify the controller 1110 of the fact, while if there nofile which is opened, the NAS 16100 determines that the accessibility ofthe logical volume 1140 has been lowered, to notify the controller 1110of the fact.

In addition to the trigger that the NAS 16100 has received theabove-described open request, when the NAS 16100 has received a mountrequest of a file system or a directory included in the logical volume1140 from the host computer 1200, the NAS may determine that theaccessibility of a corresponding logical volume 1140 has been raised, tonotify the controller 1110 of this information. Similarly, in additionto the trigger that the NAS 16100 has received a close request, when theNAS 16100 has received an unmount request of a file system or adirectory from the host computer 1200, the NAS may determine that theaccessibility of a corresponding logical volume 1140 has been lowered,to notify the controller 1110 of this information.

In addition, the number determination reference of the file open may beany other numbers than zero, and it may be determined that theaccessibility has been raised based on a file open request. Further, itmay be determined that the accessibility has been lowered based on afile close. Similarly, the determination reference of the number ofclients in process of mount may be any other numbers than zero. Inaddition, using any other methods than this, it may be determined thatthe accessibility has been raised based on a mount request, and it maybe determined that the accessibility has been lowered based on anunmount request. Moreover, using other evaluation methods, it may bedetermined that the accessibility has been raised with file open/mount.

FIG. 17 shows an example of information and programs stored in the NASmemory 16120.

File logical volume correspondence information 16121 is informationconcerning the corresponding relation for acquiring an identifier of alogical volume 1140 including data of a file and an address which candesignate data regions within the logical volume, from file names orother identifiers designated by the host computer 1200. Further, thefile logical volume correspondence information 16121 may includeinformation concerning access authority and access time, such as latestupdate time, creation time, latest reference time, etc. of files.

Logical volume counter information 16122 is information, for everylogical volume 1140, for managing the number of clients that are beingcurrently mounted or the number of files that are being currentlyopened.

A file access processing program 16123 is a program executed by the CPU16110 when it receives and processes access requests, such as mount andunmount of a file system or a directory, as well as a file open request,a file close request, and a file read/write request from the hostcomputer 1200.

When the file access processing program- executed at the CPU 16110 hasreceived a file read request, the file access processing program 16123refers the file logical volume correspondence information 16121 torecognize a logical volume 1140 and a data region to include requireddata, and transfer the data and completion message to the host computer1200. When the program has received a file write request, the fileaccess processing program 16123 refers the file logical volumecorrespondence information 16121 to recognize a logical volume 1140 anda data region to write data, then write the data received from the hostcomputer 1200, and then transmits completion message to the hostcomputer 1200.

FIG. 18 shows an exemplary configuration of the logical volume counterinformation 16122. The logical volume counter information 16122 hasentries in which the following information is registered for everylogical volume 1140.

A logical volume identifier 18010 is an entry with which information ofan identifier of the logical volume 1140 is registered. An open counter18020 is an entry with which information concerning the number of filesincluded in a logical volume 1140 that is being currently opened isregistered. A mount counter 18030 is an entry with which informationconcerning the number of host computers 1200 that is being mounting afile system included in a logical volume 1140 is registered.

FIG. 19 shows an exemplary processing sequence when the NAS 16100 hasreceived a mount request from the host computer 1200. The followingprocessing sequence can be achieved as the CPU 16110 executes the fileaccess processing program 18123. In addition, it is assumed in thefollowing description that the NAS 16100 directs the controller 1110 toexecute the processing described in the first embodiment, such as thestarting of the disk device 1130, with a mount request or an unmountrequest as a trigger. However, as described above, the form of thetrigger is various.

The NAS 16100 receives a mount request, along with information (anidentifier or a directory name of a logical volume 1140 where a filesystem exists or information that identifies other files, directoriesand logical volumes) that defines a target to be mounted (S19010). TheNAS 16100 specifies a logical volume 1140 to include a file system or adirectory as a target to be actually mounted, from the information thatdefines the received mount target. In addition, the file logical volumecorrespondence information 16121 may be used for the specifying(S19020).

Next, the NAS 16100 confirms the number of host computers 1200 which arebeing mounting the specified logical volume 1140 by referring to thelogical volume counter information 16122 (S19030).

If any host computer 1200 that counts the specified logical volume 1140does not exist, the NAS 16100 directs the controller 1110 to execute theaccessibility improvement direction acceptance program 2010 by using thespecified logical volume 1140 as an argument, and then waits theresponse. The controller 1110, which has received the direction, startsany one or both of the disk device 1130 and the fan 1150 correspondingto the logical volume 1140, if possible, in consideration of electricpower consumption and calorific power similar to the first embodiment,and transmits the result as a response to the NAS 16100 (S19040).

The NAS 16100, which has received the response from the controller 1110,confirms whether or not the content of the response is the content thatthe starting of the disk device 1130 has succeeded (S19050).

If the starting of the disk device 1130 has succeeded, the NAS 16100performs mount processing of a network file system on the specifiedlogical volume. Thereafter, the NAS 16100 adds one to a numberregistered in the mount counter 18130 of the logical volume counterinformation 16122, notify the host computer 1200 of completion of themount, and then completes the processing (S19060).

Meanwhile, if the starting of the disk device 1130 has failed, the NAS16100 notifies the host computer 1200 of failure of the mount, and thencompletes the processing. At this time, the NAS 16100 may include amessage that the disk device could not be started due to the electricpower consumption and cooling heat quantity, as a reason for the failureof the mount, in the notification to the host computer 1200 (S19200).

FIG. 20 shows an exemplary processing sequence when the NAS 16100 hasreceived an unmount request from the host computer 1200. This processingcan also be achieved as the CPU 16110 executes the file accessprocessing program 18123.

The NAS 16100 receives an unmount request, along with information (anidentifier or a directory name of a logical volume 1140 where a filesystem exists or information that identifies other files, directoriesand logical volumes) that defines a target to be unmounted, from thehost computer 1200 (S20010). The NAS 16100 specifies a logical volume1140 to include a file system or a directory as a target to be actuallyunmounted, from the information that defines the received unmounttarget. In addition, the file logical volume correspondence information16121 may be used for the specifying (S20020).

Next, the NAS 16100 performs unmount processing of a network filesystem, then subtracts one from a number registered in the mount counter18030 of the logical volume counter information 16122 about thespecified logical volume 1140, and notify the host computer 1200 ofcompletion of the unmount (S20030). Next, the NAS 16100 confirms thenumber of host computers 1200 which are being mounting the specifiedlogical volume 1140 by referring to the logical volume counterinformation 16122 (S20040).

If the number of any host computer 1200 that counts the specifiedlogical volume 1140 is zero, the NAS 16100 directs the controller 1110to execute the accessibility degradation direction acceptance program2020 by using the specified logical volume as an argument. Thecontroller 1110, which has received the direction, stops any one or bothof the disk device 1130 and the fan 1150, if possible, and completes theprocessing (S20050). Meanwhile, if the number of the host computers 1200that are being mounting the specified logical volume 1140 is one ormore, the NAS 16100 completes the processing directly (S20060).

Next, an example in which the NAS 16100 directs the controller 1110 toexecute the processing described in the first embodiment, such asstarting of the disk device 1130, with a file open request or a fileclose request as a trigger.

FIG. 21 shows an exemplary processing sequence when the NAS 16100 hasreceived a file open request from the host computer 1200.

The NAS 16100 receives a file open request including information (filenames and other identifiers) that defines a file to be opened (S21010).The NAS 16100 specifies a logical volume 1140 to include a file as atarget to be actually opened, from the received information. Inaddition, the file logical volume correspondence information 16121 maybe used for the specifying (S21020).

Next, the NAS 16100 confirms the number of files that are included inthe specified logical volume 1140 and are being opened, by referring tothe logical volume counter information 16122 (S21030).

If the number of files that are included in the specified logical volume1140 and are being opened is zero, the NAS 16100 directs the controller1110 to execute the accessibility improvement direction acceptanceprogram 2010 by using an identifier of the specified logical volume 1140as an argument, and then waits the response from the controller 1110.The controller 1110 starts any one or both of the disk device 1130 andthe fan 1150 in consideration of electric power consumption andcalorific power. Then, the controller 1110 transmits the result as aresponse to the NAS 16100 (S21040).

Next, the NAS 16100 determines whether or not the content of theresponse received from the controller 1110 is the content that thestarting of the disk device 1130 has succeeded (S21050).

Next, if the response from the controller 1110 include the content thatthe starting of the disk device 1130 has succeeded, the NAS 16100executes file open processing of a network file system, then adds one toa number registered in the open counter 18020 of the logical volumecounter information 16122, corresponding to the specified logical volume1140, notify the host computer 1200 of completion of the open, andcompletes the processing (S21050).

Meanwhile, if the response from the controller 1110 includes the contentthat the starting of the disk device 1130 has failed, the NAS 16100notifies the host computer 1200 of failure of the open, and thencompletes the processing. At this time, the NAS 16100 may include amessage that the disk device 1130 could not be started due to theelectric power consumption and cooling heat quantity, in thenotification of the open failure.

FIG. 22 shows an exemplary processing sequence when the NAS 16100 hasreceived a file close request from the host computer 1200. Thisprocessing can also be achieved as the CPU 16110 executes the fileaccess processing program 18123.

The NAS 16100 receives a file close request including information (filenames, file handles, and other identifiers) that defines a file to beclosed (S22010). Next, the NAS 16100 specifies a logical volume 1140 toinclude a file system or a directory as a target to be actually closed,from the information that defines the received file close target. Inaddition, the file logical volume correspondence information 16121 maybe used for the specifying (S22020).

Next, the NAS 16100 performs file close processing of a network filesystem, and then subtracts one from a number registered in the opencounter 18020 of the logical volume counter information 16122,corresponding on the specified logical volume 1140. Then, the NAS 16100notifies the host computer 1200 of the completion of the file close(S22030).

Next, the NAS 16100 confirms the number of files which are included inthe specified logical volume 1140 and are being opened, by referring tothe logical volume counter information 16122 (S22040).

If the number of files that are included in the specified logical volume1140 and are being opened is zero, the NAS 16100 directs the controller1110 to execute the accessibility degradation direction acceptanceprogram 2020 by using an identifier of the specified logical volume 1140as an argument. The controller 1110 stops any one or both of the diskdevice 1130 and the fan 1150, if possible, and completes the processing(S22060). Meanwhile, if the number of files that are included in thespecified logical volume 1140 and are being opened is one or more, theNAS 16100 completes the processing directly (S22060).

In addition, the processing sequence of file open and mount has beendescribed, assuming that, if the controller 1110 could not start thedisk device 1130, the controller 1110 does not register a direction fromthe NAS 16100 with a waiting queue. However, as other methods, it isconceivable to adopt a method in which, if the controller 1110 could notstart the disk device 1130, the controller 1110 register a directionfrom the NAS 16100 with a waiting queue. In this case, it is conceivableto adopt a method in which the NAS 16100 transmits notification of opencompletion and mount completion to the host computer 1200, after thecontroller 1110 starts the disk device 1130 based on the waiting queueso that access to the logical volume 1140 becomes possible, instead ofthe notification of open failure in the above-described processingS19200 and S21200.

It is also conceivable to adopt a method in which, if the starting timeof the disk device 1130 is long (including a case in which, ifregistered with the waiting queue, the own starting time of the deviceis long), the NAS 16100 transmits a message such that the host computer1200 issues a request once again, to the host computer 1200. By doingso, the non-response time from reception of a request to reply theretocan be reduced, and erroneous recognition of a failure of the disksystem 16000 can be avoided.

FIG. 25 shows an exemplary configuration of a system to which a fourthembodiment is applied. Generally, a system manager calculates consumableelectric power using the storage system 1000, on the basis of electricfees (hereinafter, referred to as “electric power cost”) that are paid(can be paid) to an electric power company. Therefore, in the presentembodiment, the manager sets information of the electric power cost inthe storage system 1000, whereby the storage system 1000 automaticallysets a target electric power commensurate to the electric power cost inthe storage system 1000 itself. More specifically, on the basis of atarget electric power cost input by the manager of the storage system1000, the storage system 1000 converts the target electric power costinto a target electric power, using a conversion expression for theelectric power provided by the electric power company and the electricpower cost.

Here, the present embodiment is different from the first to thirdembodiments in that an electric power cost=electric energy conversionprogram 25001 and target electric power cost information 25002 are addedto the management memory 1310 of the management computer 1300, and anelectric power cost information providing computer 25010 is connected tothe storage system 1000 over a network 25020.

The electric power cost information providing computer 25010 is acomputer that provides information concerning an electric power cost(for example, an amount of money corresponding to electric energy usedper unit time). An electric power cost information providing program25012 and electric power cost information 25011 are stored in a memoryin the electric power cost information providing computer 25010. It isconceivable that the electric power cost information providing computer25010 is possessed by an electric power company. The electric power costinformation 25011 is an entry with which electric power cost informationrequired for calculating available electric power (that is, targetelectric power) from the electric power cost. As an example of theelectric power cost, on the basis of conditions, such as electric powercost, time (or date), and electric power use contract, a function forcalculating a maximum electric power which can meet the conditions isconceivable, but other methods may be adopted.

The electric power cost information providing program 25012 is a programthat is executed by the electric power cost information providingcomputer 25010 when a whole or a portion of the electric power costinformation is provided in response to a request from the managementcomputer 1300.

Next, the outline of the programs and information added to themanagement computer 1300 will be described.

Target electric power cost information 25002 is an entry that storesinformation concerning a maximum electric power cost to be targeted bythe storage system 1000. It is also conceivable that the information isinput by the manager of the storage system 1000, but the information maybe input by other methods or persons. The electric power cost=electricenergy conversion program 25001 is a program executed when themanagement computer 1300 calculates and sets an available maximumelectric power, on the basis of a maximum electric power cost to betargeted by the storage system 1000 and the information provided by theelectric power cost information providing computer 25010.

In addition, as described above, the electric power cost informationproviding computer 25010 is connected to the storage system 1000 throughthe Internet 25020. In addition, the communication method and mediumtype of the Internet 25020 may not be considered.

FIG. 26 shows an exemplary processing sequence when the managementcomputer 1300 executes the electric power cost=electric energyconversion program 25001 to calculate a target electric power frominformation concerning an electric power cost. It is assumed that theprogram is executed periodically, but the program may be executed atrandom times.

The management computer 1300 issues a request to the electric power costinformation providing computer 25010 to acquire all or some of theelectric power cost information. In addition, when the managementcomputer 1300 issues a request to the electric power cost informationproviding computer 25010, it is necessary to know a position on anetwork, of the electric power cost information providing computer 25010as an issuing destination. As a solving method, it is conceivable toinput an address of the electric power cost information providingcomputer 25010 as a request issuing destination to the managementcomputer 1300 in advance at a point of time of introduction of thestorage system 1000. It should be noted here that other methods may beused. Further, the electric power cost information 25011 may be acquiredby storing the information in advance in management computer 1300 or bycashing the information for a predetermined period of time. That is, themanagement computer acquires the information in advance or acquires theinformation as needed (Step 26000).

Next, the management computer 1300 confirms whether or not (A) targetelectric power cost information 25002 or (B) electric power costinformation 25011 has changed (that is, it has been changed by a manageror an electric power company, etc.), and if the information is notchanging, the management computer completes the processing (Step 26010).If the information is changing, the management computer 1300 calculatesa target electric power from the target electric power cost information,using a calculating expression included in the electric power costinformation (Step 26020).

Next, if the calculated target electric power is equal to a conventionaltarget electric power, the management computer 1300 completes theexecution of the program (Step 26030). If not, the management computer1300 compares the calculated target electric power with a currently usedelectric power acquired from the disk system 1100 (Step 26040). If thecalculated value is small, the management computer 1300 displays on ascreen output device, a message that the target electric power cannot beset because the currently used electric power is greater, and completesthe processing (Step 26060). Meanwhile, in Step 26040, if the calculatedvalue is greater than the currently used electric power, the managementcomputer 1300 updates the target electric power of the disk system 1100to the calculated value and completes execution of the program (Step26050).

In addition, it has been described in the above embodiments that thedisk device 1130 is started-at the time of reception of the notificationof a rise in availability of a logical volume that is notified from thehost computer, etc. However, the disk device may be started at othertime. Further, an example in which rises in the usability of a logicalvolume are determined as host computers analyze patterns of access tothe logical volume is considered.

In addition, as embodiments of the invention, the followingconfigurations are also considered. Specifically, an information systemincludes a host computer and a disk system. The host computer has afunction to access to a logical volume defined in the disk system. Thedisk system has at least one disk device and a power supply module, andhas a function to convert the logical volume to the disk device. Thehost computer has a unit that notifies the disk system of a logicalvolume whose possibility to be accessed in the future has been improved.The disk system has a unit that starts a disk device corresponding tothe logical volume by comparing the electric power capacity of the powersupply module with an electric power consumed by a disk device to benewly started in addition to a disk device that is being currentlystarted.

Further, in the above configuration, it is conceivable to adopt aconfiguration in which the disk system further includes at least onefan, and the disk system has a unit that starts a disk devicecorresponding to the logical volume by comparing a cooling heat quantityof the fan with a calorific power of the disk device to be newly startedin addition to the, disk device which is being started.

Moreover, in the above configuration, it is also conceivable to adopt aconfiguration in which, when the disk device corresponding to thelogical volume is started, the disk system further includes a unit thatrecognizes a fan required to be newly started, to start the fan.

Further, in the above configuration, the host computer may have a unitthat notifies the disk system of a logical volume whose possibility tobe accessed in the future has been lowered, and the disk system may havea unit that recognizes a disk device corresponding to the logicalvolume, to stop the disk device.

Moreover, in addition to the above configuration, it is also conceivableto adopt a configuration in which the disk system further includes aunit that recognizes a fan to be newly started when the disk devicecorresponding to the logical volume is stopped, to stop the fan.

Further, as another configuration, it is also conceivable to adopt thefollowing configuration. Specifically, an information system includes ahost computer and a disk system. The host computer accesses to a hostlogical volume. The disk system has at least one disk device and a powersupply module, and has a function to convert the host logical volume andthe logical volume, and a function to convert the logical volume to thedisk device. The host computer has a unit that notifies the disk systemof a logical volume whose possibility to be accessed in the future hasbeen improved. The disk system has a unit that starts a disk devicecorresponding to the logical volume by comparing the electric powercapacity of the power supply module with an electric power consumed by adisk device to be newly started in addition to a disk device that isbeing currently started.

Moreover, in the above configuration, it is also conceivable to adopt aconfiguration in which the disk system further includes at least onefan, and the disk system has a unit that starts a disk devicecorresponding to the logical volume by comparing a cooling heat quantityof the fan with a calorific power of the disk device to be newly startedin addition to the disk device which is being started.

Further, in the above configuration, it is also conceivable to adopt aconfiguration in which, when the disk device corresponding to thelogical volume is started, the disk system further includes a unit thatrecognizes a fan required to be newly started, to start the fan.

Moreover, in the above configuration, the host computer may have a unitthat notifies the disk system of a logical volume whose possibility tobe accessed in the future has been lowered, and when host logical volumeallocated to the logical volume is opened, the disk system may have aunit that stops a disk device corresponding to the logical volume.

Moreover, in the above configuration, it is also conceivable to adopt aconfiguration in which the disk system further includes a unit thatrecognizes a fan to be newly stopped when the disk device correspondingto the logical volume is stopped, to stop the fan.

Further, as a different configuration, it is also conceivable to adopt adisk system including an NAS having information that acquires a logicalvolume including data of a file from a file name or an identifier, atleast one disk device, a power supply module, and a controller having afunction to converting the logical volume to the disk device. When theNAS has received a file open request from the controller, the NAS has aunit that determines that the accessibility of the logical volume hasbeen improved, on the basis of the file open request, and that notifiesthe fact. The disk system has a unit that starts a disk devicecorresponding to the logical volume by comparing the electric powercapacity of the power supply module with an electric power consumed by adisk device to be newly started in addition to a disk device that isbeing currently started.

Moreover, in the above configuration, it is also conceivable to adopt aconfiguration in which the disk system further includes at least onefan, and the disk system has a unit that starts a disk devicecorresponding to the logical volume by comparing a cooling heat quantityof the fan with a calorific power of the disk device to be newly startedin addition to the disk device which is being started.

Further, in the above configuration, it is also conceivable to adopt aconfiguration in which, when the disk device corresponding to thelogical volume is started, the disk system further includes a unit thatrecognizes a fan required to be newly started, to start the fan.

Further, in the above configuration, it is also conceivable to adopt aconfiguration in which the NAS has a unit that determines that theaccessibility of the logical volume has been lowered, when the NAS hasreceived a file close request from the controller, on the basis of thefile close request, and notifies the fact, and the disk system has aunit that stops a disk device corresponding the logical volume.

Alternatively, in the above configuration, it is also conceivable toadopt a configuration in which the disk system further includes a unitthat recognizes a fan to be newly stopped when the disk devicecorresponding to the logical volume is stopped, to stop the fan.

1. A storage system comprising: a controller; a disk device connected tothe controller; a cooling device that cools the disk device; and a powersupply module that supplies electric power to the controller, the diskdevice, and the cooling device, wherein the controller determineswhether or not the disk device is to be started, on the basis ofinformation concerning heat quantity generated by starting the diskdevice, the cooling capacity of the cooling device, and electric powerrequired to drive the disk device.
 2. A storage system according toclaim 1, wherein the controller also considers information concerningelectric power required to drive the cooling device when it determineswhether or not the disk device is to be started.
 3. A storage systemaccording to claim 2, wherein the controller creates a logical volumethat is a storage region on the basis of a storage region in the diskdevice, wherein the controller is connected to a computer, and whereinthe controller determines whether or not the disk device is to bestarted, when the logical volume is used by the computer.
 4. A storagesystem according to claim 3, wherein the controller determines whetheror not the cooling device is to be stopped, on the basis of informationconcerning heat quantity that is reduced by stopping the disk device. 5.A storage system according to claim 3, wherein the cooling device is afan, wherein the controller decreases the number of rotations of thefan, on the basis of the information concerning heat quantity that isreduced by stopping the disk device.
 6. A storage system according toclaim 3, wherein the controller determines whether or not the diskdevice corresponding to the logical volume is to be stopped, when thelogical volume is no longer used by the computer.
 7. A storage systemaccording to claim 1, further comprising: information concerning apredetermined threshold value about electric power, wherein thecontroller determines whether or not the disk device is to be started,on the basis of whether or not an electric power consumed by the storagesystem by driving the disk device exceeds the predetermined thresholdvalue.
 8. A storage system according to claim 7, wherein the thresholdvalue is the maximum electric power of the power supply module.
 9. Astorage system according to claim 7, wherein the threshold value is avalue to be set by a user who uses the storage system.
 10. A storagesystem according to claim 9, wherein the controller further determineswhether or not driving of the cooling device is necessary.
 11. A storagesystem according to claim 10, wherein if there is any cooling devicerequired to be driven by driving the disk device, the controllerdetermines whether or not the disk device and the cooling device is tobe driven, on the basis of whether or not an electric power consumed bythe storage system by driving the disk device and the cooling deviceexceeds the predetermined threshold value.
 12. A storage systemaccording to claim 11, wherein the controller changes informationconcerning determination on whether or not the disk device is to bedriven, on the basis of a change in the cooling capacity of the coolingdevice.
 13. A storage system according to claim 12, wherein the changein the cooling capacity of the cooling device is a change based onopening/closing of a cover in a housing that contains the storagesystem.
 14. A storage system according to claim 13, wherein thecontroller determines whether or not the disk device is to be started,when the logical volume is mounted on the computer.
 15. A storage systemaccording to claim 14, wherein the controller determines whether or notthe disk device is to be stopped, when the logical volume is unmountedfrom the computer.
 16. A storage system according to claim 15, whereinthe controller determines whether or not the disk device is to bestarted, when an open command of a file stored in the logical volume istransmitted from the computer.
 17. A storage system according to claim16, wherein the controller determines whether or not the disk device isto be started, when a close command of a file stored in the logicalvolume is transmitted from the computer.
 18. A storage system accordingto claim 11, wherein the controller monitors a failure of a device inthe storage system, and when the failure occurs, the controller changesinformation concerning determination on whether or not the disk deviceis to be driven.